JPH09182364A - Fixed shaft oscillation motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a fixed shaft oscillation motor in which current consumption is reduced while preventing an unnecessarily large air gap from being formed by preventing axial vibration of rotor in starting and rotating thereof and mechanical noise is also reduced in starting and rotating. SOLUTION: One end 3a of a shaft 3 is secured to a part 1 of a housing H and an eccentric rotor R is pivoted to the other end 3b and urged toward the fixed side using the magnetic force of a field magnet M. The fixed shaft oscillation motor can employ an axial gap type or radial gap type structure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixed shaft type vibration motor suitable for use in a silent notification means such as a portable communication device.

[0002]

2. Description of the Related Art An efficient small DC motor is used as a silent notification means of a portable communication device such as a pager,
An eccentric weight is attached to a rotary shaft protruding to the outside of the housing, and vibration is obtained by utilizing the imbalance of the eccentric weight. Recently, if only vibration is to be obtained, an output shaft is not required, and therefore, a rotor in which a built-in rotor is eccentric to obtain vibration is beginning to appear. (See Japanese Patent Publication No. 7-85636, etc.)

In order to rotate the built-in eccentric rotor, it is not necessary to rotate the shaft.
No. 43 and Japanese Patent Application No. 7-264831 are proposed. That is, as shown in FIGS. 1 and 4 of Japanese Patent Publication No. 6-81443, one end of a shaft is fixed to one of a housing composed of a case and a bracket, and a rotor eccentric from the open end to this shaft is used. It is rotatably supported via a bearing integrated with the rotor.

[0004]

The fixed shaft type vibration motor as described above does not need to pursue the high coaxiality of the bearings arranged on the end face of the housing, unlike the rotary type, and has a simple structure and is mass-produced. It has high performance and a large market record. In recent mobile devices, the battery itself has been downsized and the capacity has decreased, and it is desired that the active components such as a vibration motor to be mounted consume as little current as possible. An object of the present invention is to further improve the shaft fixed vibration motor as described above so that a low current consumption can be obtained. Another object of the present invention is, in the case of an eccentric rotor having a single bearing part, to prevent axial deviation at the time of starting and rotating the rotor so that the air gap can be set small and the starting It is to avoid mechanical noise and trouble of power supply means.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention has a structure in which a bearing portion for preventing the rotational force of an eccentric rotor is minimized and a structure for urging the rotor in one direction. This is achieved in combination, and in this way, reduction of brake loss and prevention of rotor shake are achieved.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION According to the present invention, one end of a shaft is fixed to a case or a bracket, and an eccentric rotor is rotatably supported on the shaft. The other end is pivotally supported and the magnetic force of the field magnet is used to urge it toward the fixed side.

In the case of implementing a flat axial air gap type coreless motor as one of the concrete forms, a plurality of air-core armature coils are slidably formed in the housing so that at least a portion slidingly contacting the shaft is slidable. While integrating with resin,
An eccentric rotor having a magnetic plate as a part of the urging means, a field magnet for giving a magnetic force to the rotor from an axial direction through a gap, and a rotor arranged inside the field magnet. It is preferable to have a power supply means for supplying power to the.

Further, the above-mentioned plurality of air-core armature coils are arranged so as to be biased to one side so that the coil having a driving function does not come to the side opposite to the center of gravity, and form a disc when integrated with a synthetic resin as a rotor. It is better not to.

Further, it is preferable that the synthetic resin integrated as the rotor is a high specific gravity member having a specific gravity of 3.5 or more at least in a portion contributing to the movement of the center of gravity.

Furthermore, it is preferable that the magnetic plate is constructed so that the center portion thereof is inside the diameter of the shaft in order to reinforce the pivot bearing portion of the shaft.

As a second specific form, when the invention is applied to a radial air gap type motor having a magnetic circuit member in a rotor, an armature coil having the magnetic circuit member and an eccentric means are provided inside the housing. An eccentric rotor that is pivotally supported on the shaft, a field magnet that gives a magnetic force to the rotor through a gap in the radial direction, and a power feeding means that gives electric power to the rotor are provided. It is preferable that the magnetic centers of the circuit member and the field magnet are offset from each other.

The magnetic circuit member may be of a slotless type, and an eccentric member may be arranged inside thereof.

In the shaft-fixed vibration motor configured as described above, since the eccentric rotor is pivotally supported at the end of the shaft to reduce the bearing area, brake loss that hinders rotation is reduced and the rotor itself is reduced. Even if the rotor is eccentric, the rotor is not tilted by being uniformly biased to the fixed side.

[0014]

[First Embodiment] A first embodiment of the present invention will now be described with reference to FIG. 1, which is a sectional view of a main portion of a flat axial gap type coreless vibration motor. In the figure, the housing H is
It is composed of a shallow inverted dish-shaped case 1 and a bracket 2 fitted in an opening of the case 1, and one end 3a of a shaft 3 is press-fitted and held in the center of the case 1. The other end 3b of the shaft 3 is rounded and separated from the ceiling portion of the bracket 2 by a predetermined size, and the eccentric rotor R is made of synthetic resin J having high specific gravity and good slidability.
Is rotatably mounted and is pivotally supported at the other end 3b by a non-penetrating bearing portion Ra. A magnetic plate F made of a thin silicon steel plate for axially urging is embedded in the eccentric rotor R so that the inner diameter is inside the diameter of the shaft, and is arranged in the case 1 on the opposite side while having a reinforcing function. The magnetic field magnet M receives the magnetic force and the eccentric rotor R is urged to the fixed side of the shaft. A flat plate commutator C made of a printed wiring board is attached to the field magnet side of the rotor R, and the terminal T is provided inside the field magnet M.
The brush B planted in the brush base B1 is slidably contacted with the brush base B1 to receive electric power.

The detailed structure of the eccentric rotor R is as follows.
As shown in FIG. 2, that is, in the figure, the rotor R is a flat plate commutator C made of a printed wiring board and air core armature coils L1 and L2 having three equilateral triangular inner diameters.
And L3 are arranged on one side at an arrangement pitch of 60 °, and tungsten alloy powder is blended with polyamide to integrally mold slidable resin J having a high specific gravity (density of 5 or more). The magnetic field is received from an 8-pole magnet M magnetized at a magnetization opening angle (45 °) equal to. The flat plate commutator C is composed of 12-pole segments C1, C2 ... C12 formed by gold-plating a pattern printed and wired at an opening angle of 30 °, and through holes H1, H2, H3 ... Via H12 to the segments C1, C4, C7 and C10 and C2
C5, C8 and C11 and C3, C6, C9 and C
12 are short-circuited by the conductor patterns D1, D2 and D3, respectively. In the figure, P1, P2 and P3 are patterns for collectively soldering the winding end terminals of the air core armature coils L1, L2 and L3, and P4, P5 and P6 are patterns for connecting the winding start terminals. Of these patterns, P4 has the conductor pattern D1 and P5 has the conductor pattern D3.
, And D2 is connected to P6. On the other hand, the brushes B, B slidingly contacting such a commutator C
As shown in FIG. 3, the sliding contact sides B2 and B2 formed in an arc shape from the base ends B1 and B1 when viewed from the plane and folded into the inner diameter.
Is a switchback type and is slidably contacted with the commutator C from the axial direction so that the slidable contact portions B3, B3 are located at a position of 135 ° (3 times the magnetic pole). Rotor R configured in this way
Since is eccentric, centrifugal force is generated during rotation and external vibration is generated. The weight of the rotor R causes a strong centrifugal force because the specific gravity of the resin is large. The rotation principle using such an eccentric rotor is described in detail in Japanese Patent Application No. 7-264831 previously proposed by the present applicant, and is not the gist of the present invention. Omit it.

In the first embodiment, the synthetic resin itself having good slidability was used as the bearing, but as a modification, as shown in FIG. 4, the resin bearing S1 having good slidability only in the portion in contact with the shaft.
Or use a blind type sintered oil-impregnated bearing and others with a specific gravity of 8
A high specific gravity nylon member may be used.

As a further modification, as shown in FIG. 5, the air-core armature coil may be evenly distributed over the whole or one side may be provided with the non-magnetic eccentric weight W as a reinforcing means attached to the rotor. .

FIG. 6 is a longitudinal sectional view of an essential part of a radial void type having a slotless type magnetic circuit member as a second embodiment of the present invention, and FIG. 7 is a sectional view taken along line AA of FIG. FIG. In the figure, the housing H1 is
It is composed of a bag-shaped case 11 and a bracket 2 fitted in the opening of the case 11, and one end 3a of a shaft 33 is press-fitted and held in the center of the bracket 2. The other end 3b of this shaft 33
Is rounded and separated from the ceiling of the case 11 by a predetermined dimension, and the eccentric rotor R1 is pivotally supported by the other end 3b of the shaft 33 through the slidable synthetic resin J2. It is installed. In this eccentric rotor, the slotless iron core 4 formed by laminating a thin silicon steel plate as a magnetic circuit member moves the center of gravity to one side, so that a half-moon shaped through hole 4a is provided on the opposite side to the synthetic resin J2. Are integrated in. This synthetic resin J2 has a core cover portion J2a and a winding guide pole portion of the armature winding 5 which is J
2b and the bearing J2c are integrated respectively.
The armature winding 5 is composed of six armature coils 5a, 5b, 5c, 5d, 5e and 5f wound around the guide hole portion J2b so as not to overlap each other. Since the brush B and the flat plate commutator C are the same as those in the first embodiment, their description will be omitted.

On the outer circumference of the eccentric rotor, a cylindrical field magnet M1 made of a rare earth plastic is fixed inside the case 11 and is magnetized in four poles alternately in N and S. In order to urge the eccentric rotor R1 toward the fixed side of the shaft (bracket side), the center of the field magnet M1 is intentionally shifted toward the bracket side from the center of the magnetic circuit member.

In the above embodiment, the bearing is made of synthetic resin itself. As a modification, in order to reduce the projected area of the bearing, as shown in FIG. 8, the resin bearing portion is thinned to have a thin sleeve in the opening. The rotor R2 may be a rotor R2 in which the die-sintered bearing S2 is fitted and the inside is hollow. In addition, J2d in the figure
Is a bushing as an oil barrier means formed by coating a fluorine-based solution. The eccentric rotors R1 and R2 as described above receive the magnetic force of the field magnet M1 and uniformly urge them without inclining to the bracket side. By doing so, since the slotless iron core is used, the cogging torque is smaller than that of the one having salient poles (teeth), and the cored can be easily started. Since the center of gravity is on the opposite side due to the half-moon type through hole 4a, a large centrifugal force is generated during rotation and vibration is generated.

In the second embodiment, the through hole 4a is used as the eccentric means. However, the through hole may be provided on both sides and a high specific gravity member made of tungsten alloy may be embedded in one of the through holes.

[0022]

The present invention has the following effects by being implemented in the form described above.

In the fixed shaft type vibration motor, the eccentric rotor is pivotally supported at the tip (the other end) of the shaft and is urged toward the fixed side by utilizing the magnetic force of the field magnet. Is extremely small and can be uniformly biased, so that the rotor itself does not shake. Therefore, if the axial air gap type flat coreless motor is used, the air gap can be provided to be extremely small, that is, ultra-thin, and even in the radial air gap type motor, there is no need to set the air gap unnecessarily large. By eliminating, it is possible to reduce mechanical noise at the time of starting or rotating.

In the flat axial gap type coreless motor which is eccentric by the air-core armature coil itself, a special eccentric weight is required and the structure is simplified.

Further, since the synthetic resin integrated as the eccentric rotor is used as the high specific gravity member, a large centrifugal force can be generated.

Further, since the pivot bearing portion is also reinforced by a part of the biasing means, the pivot bearing portion can be thinned.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a first embodiment adopted in a flat axial gap type coreless motor as a shaft fixed vibration motor of the present invention.

FIG. 2 is a transverse sectional view of the same main part.

FIG. 3 is a plan view of a brush used in the motor.

FIG. 4 is a cross-sectional view of an essential part of a modified example of the first embodiment.

FIG. 5 is a cross-sectional view of an essential part of another modification of the first embodiment.

FIG. 6 is a longitudinal cross-sectional view of a main part of a motor having a radial air gap type slotless iron core as a second embodiment of the present invention.

FIG. 7 is a cross-sectional view taken along the line AA of FIG.

FIG. 8 is a cross-sectional view of an essential part of a modified example of the second embodiment.

[Explanation of symbols]

 H, H1 housing 1, 11 case 2 bracket R, R1 eccentric rotor Ra bearing J, J1 synthetic resin 3, 33 shaft 3a shaft fixed end (one end) 3b shaft end (other end) F magnetic plate M, M1 field magnet 4 magnetic circuit member

Claims (7)

[Claims] 1. An end of a shaft is fixed to a part of a housing,
In a fixed shaft type vibration motor in which a rotor eccentric to this shaft is rotatably supported by a shaft bearing portion arranged in the center, the eccentric rotor is pivotally supported at the other end of the shaft and a field magnet A fixed shaft type vibration motor that uses a magnetic force to urge it toward the fixed side. 2. A plurality of air-core armature coils are integrated in a housing with a synthetic resin having at least the bearing portion made slidable, and a magnetic plate is arranged as a part of the biasing means. A eccentric rotor, a field magnet that gives a magnetic force to the rotor in the axial direction through a gap, and a flat shaft provided inside the field magnet to supply power to the rotor. The shaft fixed vibration motor according to claim 1, which is a directional air gap type coreless motor. 3. The plurality of air-core armature coils are arranged so as to be biased to one side so that a coil having a driving function does not come to the side opposite to the center of gravity, and a disc is not formed when integrated as a rotor. Item 3. A shaft fixed vibration motor according to item 1 or 2. 4. The shaft fixed vibration motor according to claim 1, wherein at least a part of the synthetic resin integrated as the rotor is a high specific gravity member having a specific gravity of 3.5 or more. 5. The shaft fixing according to any one of claims 1 to 4, wherein the magnetic plate is configured such that a center portion thereof is located inside a diameter of the shaft for reinforcing a pivot bearing portion of the shaft. Type vibration motor. 6. An eccentric rotor formed by arranging an armature coil having a magnetic circuit member and an eccentric means inside the housing and pivotally supporting the shaft, and a magnetic force is applied to the rotor from a radial direction through a gap. The shaft fixing according to claim 1, wherein a field magnet to be given and a power feeding means to give electric power to the rotor are provided, and as the biasing means, a magnetic circuit member and a field magnet are of a radial gap type in which magnetic centers are displaced from each other. Type vibration motor. 7. The shaft-fixed vibration motor according to claim 6, wherein the magnetic circuit member is a slotless type, and an eccentric means is arranged inward of the slotless type.